Apparatus for charging and sealing metallic bulbs



Sept. 6, 1949. H. FQTOMASEK EI'AL 2,431,042

APPARATUS FOR CHARGING AND SEALING METALLIC BULBS Filed June 15, 1945 3 Sheets-Sheet 1 v N m INVENTORS.

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Sept. 6, 1949.

Filed June 15, 1945 H. F. TOMASEK ET AL 1,042

APPARATUS FOR CHARGING AND SEALING METALLIC BULBS 3 Sheets-Sheet 2 I R Q N J LL Sept. 6, 1949.

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Next Cycle [1% A PERIODS patented Sept. 6, 194?) Q UNITED STATES "PATENT, OFFICE APPARATUS FOR CHARGING ND SEALING METALLIC BULBS Herbert F. Tomasek, St. Louis, Mo., and Lawrence T. Ward, East Orange, N. J assigncrs, by mesne assignments, to Knapp-Monarch Com pany, St. Louis, Mo., a corporation of Delaware Application June 15, 1945, Serial No. 599,594 6 Claims. (01. 219-4) 1 Our present invention relates to an apparatus Fig. is a sectional view on the line 5-5 of Fig. for charging and sealing metallic bulbs of the 3 showinga gas valve; kind shown in Weida application, Serial No. Figure 5a is an enlarged sectional View through 535,893, filed May 16, 1944, now Patent No. the top of the bulb and the cap; and 2,425,448, dated August 12, 1947, and Ward appli- Fig. 6 is a diagrammatic view showing our apcation, Serial- No. 587,454, filed April 10, 1945, paratus and including a schematic diagram of a now abandoned. complete cycle of operation thereof and the rela- One object of the invention is to provide an tion of the operations of different elements of the apparatus of this character which can be manuapparatus during such cycle. ally initiated as to its operating cycle and will 10 0n the accompanying drawings we have used thereafter automatically charge the bulb with the reference character F to indicate a frame of gas and weld the metallic cover on the bulb to our apparatus on which is mounted a rotatable form an integral bulb and cap combination after table T and a head H. The head H is normally which the bulb may be removed from the apin the position of Fig. 1 but is mounted for moveparatus. l5 ment downwardly from this position, the head Another object of the invention is to provide a for this purpose being secured to a boss iii mountpressure chamber around the neck of the bulb, ed. within a clam 12 of a piston rod M. The to receive the neck with a cap thereon, and into piston rod i4 is connected with a piston or ram R which any desired gas under pressure, such located within a cylinder l6. carbon dioxide (CO2) or nitrous oxide (N), 20 The head H includes a cylinder l8 in which is or any combination thereof, may be introduced mounted a secondary piston or ram R with which for charging the bulb, and the cap may then. be is connected a. piston rod 20. The piston rod 28, welded on the bulb while they are still in the as shown in Fig. 3, has an electrode 22 in its lower pressure chamber. end, and the table T has a plurality of bulb seat Still another object is to provide an apparatus 25 elements 24 projecting upwardly therefrom which of this character which is provided with an also serve as electrodes, as will hereinafter appear automatic sequence timer to cause a repeated. and which are equally spaced around the center cyclical operation of all parts of the apparatus oi rotation 260i the table T. after the first cycle is initiated manually. The head H has therein a pressure chamber 28 A further object is to provide for operating 30 into which the electrode 22 projects after passing various parts of the apparatus in proper sequence through an insulation bushing 30. The electrode and for the proper periods of time to fully charge 22 is a taper fit as at 32' in the lower end of the the bulb, weld the cover to the bulb with a welding piston rod 20 and may be removed therefrom for current of the proper duration and provide therereplacement by inserting a drill press wedge into after a forging period of proper duration. 35 a slot 34 of the piston rod 26 and tapping on it Still a further object is to provide a sequence to drive an expeller pin 36 downwardly in the timer control for the apparatus wherein the commanner standard on drill presses.

pletion of certain operations cause the subsequent The electrode 22 is preferably a good working operations to occur in their proper order. fit in the bushing 35 and, consequently, pressure With these and other objects in View, our in- 40 from the chamber 28 can pass through the bushvention consists in the construction, arrangement ing. This pressure is sealed off from atmosphere and combination of the various parts of our deby a. diaphragm of rubber, neoprene or the like, vice whereby the objects contemplated. are atand the diaphragm is of washer-like character tamed, as hereinafter more fully set forth,.pointed and of the cross-section shown in 8. its out in our claims and illustrated in the accomouter edge is sealed in the head H by gland panying drawings, wherein: and its inner edge is sealed. relative to the piston Fig. 1 is a side elevation of: the apparatus ernrodii by a fiber ring 42 and a lock nut M. Shims bodying our present invention; are provided. at 45' to regulate the pressure of the Fig. 2 is a front elevation thereof; seal around the periphery of the diaphragm 38 Fig, 3 is an. enlarged. sectional view on the line when the head H. is held in position by screws 48 tie-3 of Fig. 1, showing the parts in one position threaded into an enlarged outer end l5 of the (filling the bulb with gas). boss 10 Fig. L is a. similar sectional View showing the In the lower end of the head H is a sleeve-like parts in another position (welding the cap to the plug 50 for sealing against a bulb B below a cap bulb). or (2 on the bulb when the parts are in the position lowered by gravity of Fig. 3. A valve GV is provided for admitting gas under pressure to the pressure chamber 28 and is shown particularly in Fig. 5. The gas valve GV comprises a valve seat 52 against which a valve pin 54 is adapted to seat. Seating is effected by rotating the valve pin 54 as the pin is threaded, as indicated at 56. A lever 58 is mounted on the valve pin and is connected by a link 60 to a solenoid plunger 62. The plunger is adapted to be and raised by energization of a solenoid coil S Gas under pressure may be supplied to the gas valve GV as from a supply hose 66. This gas may be any kind suitable for charging the bulb B such as carbon dioxide or nitrous oxide or some combination of the two.

In connection with the pressure chamber 28, the sleeve 50 may have an insert of Bakelite or fiber, which preferably seats slightly imperfectly on the bulb B. This permits escape of a slight amount of gas which, due to its expansion, tends to keep the bulb cool. In this way dissipation of the heat caused by filling and welding the bulb is facilitated by the escaping gas. Inasmuch as the lower end of the piston 20 moves into the head H, there will be displacement of gas below the diaphragm 38. This is taken care of by permitting the gas to escape through a bleeder screw 68 screwed into a vent passageway 10. The bleeder screw has a groove of proper size in its side to permit escape of gas at the desired rate.

For supporting actuating fluid, such as compressed air, to the cylinders I6 and I8 for operating the rams R and R the valves V and V are provided, as shown diagrammatically in Fig. 6. The valves are illustrated in the position for raising the rams and may be reversed in position for lowering the rams by energization of solenoids S and S respectively. The valves may subsequently be returned to initial position by solenoids S and S We have also shown diagrammatically in Fig. 6 a welding switch WS for supplying current through leads 86 and 88 to the electrodes 22 and 24, respectively, and a switch S controlled by the presence of bulbs in the seat elements 24 for recycling the welding apparatus as long as the table T is supplied with bulbs. V

The various control elements just described are interconnected with a plurality of timers such as T T T, T and T which may be of the electronic type, the apparatus for which is mounted in the housings 90 and 92 and the current wires from which extend through a conduit 94 to the frame F. We have shown merely a diagrammatic arrangement in Fig. 6 for the timers in relation' to time periods and the elements of the welding apparatus, as will hereinafter be more fully explained in the description of the operation which follows.

In connection with the bleeder screw 68 there is some escape of carbon dioxide which is in the liquid phase from the chamber 28 past the electrode 22 through the bushing 30, and this gradually escapes through the vent 10 and the slot in the side of the screw 68. Of course, as it expands into the atmosphere it becomes a gas, and this efiects enough refrigeration action to keep the carbon dioxide in the liquid phase within the chamber 28.

Practical operation In the operation of our bulb charging and sealing apparatus the operator places empty bulbs B in the bulb seat elements 24 with the caps C When the table loosely mounted on the bulbs.

T has been rotated by suitable means until one of the bulbs strikes the arm of the switch S the cycle of operation of the machine commences, the switch controlling the timers T and T and the solenoid S as indicated by the dotted line 12 and the solid lines 14 and 16. The dotted lines in Fig. 6 indicate the control of one element from another, and the solid lines indicate time periods, which periods are named along the left side of Fig. 6, and which are separated at the time points A, B, C, D, E, F, G and H. For instance, the time point A indicates that the ram R starts on its downward movement, this, of course, being due to the solenoid S being energized. At time point B, timer T is energized, which results in the ram R starting downward under control of the solenoid S By this time the ram R is down. Also, at time point B the timer T is energized, which, after a time period ending at point C, when the ram R is down, causes the gas valve GV to open, due to energization of the solenoid S under control of the timer T The gas valve will subsequently be closed at time point C, or any time between it and time point E, this timing being variable, so that the gas is cut off before the welding current is on, during the time the welding current is on, or after it is cut off. The timer T after a further time period, ending at time point D, operates timer T which turns the welding current on at the welding switch WS so that current then flows across from the electrode 22 through the cap C and the bulb B to the seat 24. The parts at this time, of course, are in the position of Fig. 4, and at time point E the welding current is cut off by the timer T opening the welding switch WS. At time point F the timer T elfects energization of the solenoids S and S for causing the rams R and It to start upwardly, and at point G the timer T causes the table T to be operated as through a Geneva movement of the usual type. At point H the Geneva movement stops and the switch S is operated to start the next cycle at A again, providing there is a bulb in position at the switch S. Thus, as long as bulbs are fed to the apparatus, the machine continues to operate and will automatically stop when there are no bulbs. The operating cycles will be repeated indefinitely, until a master control is operated for cutting off the current supply.

The time periods are shown substantially equal in length, but are not necessarily so. Each time period can be adjusted as desired, as usual with electronically timed welding apparatus. Where the timers are electronic tubes they are sequentially operated, as, for instance, the timer T being operated by the timer T when it times out its period, the timer A being operated by timing out of the period for T and so on. For closing the gas valve at anywhere from point C to E, the timer T may de-energize the solenoid S at the point where the circuit decays. Likewise, the circuit for the timer T may decay at G so that the Geneva movement, started at G, will continue through its complete cycle of operation, usually controlled by mechanical means, and stop at point H and cause the table to stop at the time point indicated as H, just previous to which the switch S will have been operated if there is a bulb in the seat 24 at that position. Since electronic weld timer controls are well known in the art, we have not attempted to go into detail as to the necessary hook-up, describing only the interrelated operations in the complete cycle of operation for our apparatus.

Describing the operation of the machine a little more in detail, lowering of the ram R lowersthe head so that the sleeve 50 engages the shoulder of the bulb-B below the cap C thereon, as shown in Fig. 3, to substantially seal off the compartment 28 from atmosphere. The bulb is now ready to be charged and, accordingly, it is desirable to open the gas valve GV at this time.

After the valve is opened the gas therefromenters the chamber 28 and fills the bulb, passing readily under the loose cap. When the electrode 22 is lowered and the welding current turned on,- the weld period ensues, which weld period follows a squeeze period, during which the cap is held under pressure on the bulb. After the weld current is off, a hold period is provided for forging the weld, as it has been found that, after the weld is completed, the welded joint will be stronger if held for a period of time. The forging or hold period is terminated by the rams R and R raising to open the compartment 28 and during a clearing period wherein the chamber 28 clears the bulb B, there is no movement of the table T. Instead, the table moves only during the Geneva period which occurs after the chamber 28 has cleared the bulb, and when the Geneva movement has completed one cycle of its operation the entire recycling of the machine is in order.

Our apparatus provides a convenient means to charge metallic bulbs and weld metallic caps thereon all within a pressure chamber of minimum dimensions so that there is the least possible waste of gas discharged to atmosphere when the forging period has been completed and the head H is raised. The apparatus operates automatically to seal the pressure chamber with respect to each bulb as it comes into position at the charging and welding station and requires only the initiation of a cycle after which the cycles are repeated automatically and all functions performed in their proper order as long as there are bulbs in the machine.

The welding current is preferably supplied to the electrodes only during the peaks of the alternating current wave to secure greatest efficiency in a manner also well known. It is desirable to have the timers adjustable for the purpose of adapting the apparatus to most efficient operation, depending upon the surrounding humidity and temperature conditions. As these conditions vary, the possible speed of operation of the apparatus will also vary, and it is best to have it operate at its highest possible speed as thus a maximum of bulbs can be charged per unit of time. As far as an operator is concerned, he can readily feed one or more machines with empty bulbs and remove the filled ones as fast as the machines can perform the charging and welding operations.

Some changes may be made in the construction and arrangement of the parts of our device without departing from the real spirit and purpose of our invention, and it is our intention to cover by our claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope without sacrificing any of the advantages thereof.

We claim as our invention:

1. In an apparatus for sealing metallic necked bulbs, a bulb seat element adapted to have a bulb seated therein with a metallic cover loose on the bulb, a head movable relative to said bulb seat element and adapted to imperfectly seal against the neck of the bulb below said cover and thereby constitute a chamber surrounding said necman'eiectrode movable relative to said head and engageable under pressure with said cover, a diaphragm connection between said electrode and saidhead to seal off said chamber from atmosphere and permit movement of said electrode relative to said head, and means for supplying welding current to said electrode and said bulb seat element whereby to weld said cover to said bulb while the bulb from its neck up and said cap are under pressure in said chamber.

2. In an apparatus for sealing gas pressure bulbs of the necked type, a bulb seat element adapted to have a bulb seated therein with a cover loose onthe bulb, a head movable relative to said bulb seat element and adapted to seal against the neck of said bulb and thereby constitute a chamber surrounding said neck, an electrode movable in said head and engageable with said cover, means to seal off said chamber from atmosphere and permit movement of said electrode relative to said head, and means for supplying welding current to said electrode and said bulb seat element whereby to integrally weld said cover to said bulb.

3. An apparatus for sealing metallic bulbs having neclm comprising a movable support having a plurality of bulb seats therein, said support being movable to successively position said bulb seats at a station, said bulb seats adapted to have bulbs seated therein with metallic covers loose on the bulbs, a head movable relative to said support at said station and adapted to seal against the neck of a bulb at said station, an electrode movable relative to said head and engageable with said cover, and means for supply ing Welding current to said electrode and said support.

4. In an apparatus for sealing metallic bulbs, a bulb seat element adapted to have a bulb seated therein with a metallic cover loose on the bulb, a head movable relative to said bulb seat element and adapted to seal against the bulb wall below the cover thereon, an electrode movable relative to said head and engageable under pressure with said cover, and means for successively moving said head downwardly to seal against said bulb wall, moving said electrode downwardly to engage said cover with said bulb under pressure, pass an electric welding current through said electrode and bulb seat element to weld the cover to the bulb, hold the pressure of the electrode on the bulb during a forging period, and raise the electrode and head to permit removal of the sealed bulb from the bulb seat element.

5. An apparatus for sealing bulbs comprising a bulb seat element adapted to have a bulb seated therein with a cover on the bulb, a head movable relative to said bulb seat element and adapted to seal against the bulb below the cover thereon, an electrode movable relative to said head and engageable under pressure with said cover, means for moving said head downwardly to seal against said bulb, and timed means for successively moving said electrode downwardly to engage said cover with said bulb under pressure, passing an electric welding current through said electrode and bulb seat element to weld the cover to the bulb, holding the pressure of the electrode on the bulb during a forging period, and raising the electrode and. head to permit removal of the sealed bulb from the bulb seat element.

6. An apparatus for sealing metallic bulbs comprising a plurality of bulb seat elements, a movable support therefor, a head movable relative to said support and adapted to seal against a bulb in one of said seats below a cover on the bulb, an electrode movable relative to said head and engageable under pressure with said cover, means to manually initiate downward movement of said head and thereafter successively and automatically move said electrode downwardly relative to said head to engage said cover with said bulb under pressure, pass an electric welding current through said electrode and support to weld the cover to the bulb, hold the pressure of the electrode on the bulb during a forging period, raise the electrode and head to permit removal of a sealed bulb from the support, and move said support for positioning another bulb seat beneath said head, and timers to control the movement of said electrode and the timing of the welding and forging current periods.

' HERBERT F. TOMASEK.

LAWRENCE T. WARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 507,307 Jousset et a1. June 18, 1920 1,790,787 I Badger Feb. 3, 1931 2,007,698 Tear July 9, 1935 2,014,597 Staley Sept. 17, 1935 2,021,173 Clark Nov. 19, 1935 Payne Dec. 7, 1937 

